JP3350125B2 - Ultrasound diagnostic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for obtaining tissue information and movement information of a moving body by using a reception signal from an ultrasonic probe.

[0002]

2. Description of the Related Art Conventionally, an ultrasonic diagnostic apparatus of this type measures a signal intensity of a signal received from an ultrasonic probe, that is, a reflected echo intensity, and generates a tissue image of a subject (hereinafter, referred to as a B-mode image). A B-mode processing system and measures shift frequency information due to the Doppler effect included in the transmission / reception signal to generate a moving object moving at a desired speed, that is, a moving image of a blood cell (hereinafter referred to as a color flow mapping (CFM) image). And a CFM processing system that can combine the two images or display them on a single screen, without exposure damage such as X-ray diagnostics, and without the use of contrast agents. Other radiography systems, such as X-ray imaging systems, X-ray computed tomography systems, and magnetic resonance imaging systems, that can observe images and simultaneously observe tumors and their vegetative blood vessels. Is an indispensable apparatus in the medical field of circulatory system with no uniqueness in utility. Moreover, real-time display performance has been improved due to the progress of various technologies represented by the electronic scanning technology, and moving object measurement closer to real time has become possible, and the technology has rapidly spread.

[0003] In recent years, in the field of X-ray computed tomography apparatus and magnetic resonance imaging apparatus, three-dimensional display of skeleton, internal organs, brain, and the like has already reached the practical level. Attempts have also been made to simultaneously display the skull and intracerebral aneurysm and apply it to surgery simulation (Medical Review No. 46, pp. 25-42, 199).
2).

On the other hand, even in the above-mentioned conventional ultrasonic diagnostic apparatus, a three-dimensional display of a B-mode image (Taniguchi et al .: "Development of a clinically applicable ultrasonic three-dimensional apparatus", 60th Japan Society of Ultrasound Medicine Lecture papers pp. 17-18, 1992, etc.)
And 3D display of CFM images (Japanese Patent Application No. Hei 3-213625)
No. 3), the development of three-dimensional display has become active. However, these three-dimensional display methods are independent display methods for either the B-mode image or the CFM image, and cannot be displayed three-dimensionally by combining both images. The relationship between the tumor and its vegetative vessels could not be provided.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide an ultrasonic diagnostic apparatus capable of realizing a three-dimensional display combining a B-mode image and a CFM image. To provide.

[0006]

According to the present invention, there is provided a probe for transmitting and receiving an ultrasonic wave to and from a subject, tissue information in the three-dimensional space based on a signal received from the probe, and tissue information in the three-dimensional space. Means for obtaining movement information of a moving object, means for extracting a contour image of a portion of interest from the tissue information, means for extracting a blood flow image from the movement information, and three-dimensional images of the contour image and the blood flow image A three-dimensional data memory for storing distribution information, generating means for projecting the three-dimensional distribution information at each position while changing the viewpoint with respect to the three-dimensional space to generate a plurality of two-dimensional images; Display means for continuously displaying the two-dimensional images in a predetermined order.

[0007]

According to the present invention, three-dimensional distribution information is created by distributing the contour image of the part of interest and the blood flow image extracted from the tissue information in a three-dimensional space, and changing the viewpoint at each position. 3
By projecting the dimensional distribution information to generate a plurality of two-dimensional images and continuously displaying these two-dimensional images in a predetermined order, the three-dimensional structure of the part of interest can be changed by a visual characteristic called human motion parallax. The three-dimensional structure of the blood flow image can be simultaneously grasped.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the ultrasonic diagnostic apparatus according to the present invention will be described below with reference to the drawings. Note that the scanning method of the ultrasonic diagnostic apparatus includes linear scanning, sector scanning, and the like. Here, description will be made by taking sector scanning as an example.

FIG. 1 is a block diagram showing the configuration of this embodiment. In FIG. 1, reference numeral 1 denotes an ultrasonic probe (hereinafter simply abbreviated as “probe”) in which a plurality of piezoelectric vibrators are arranged in parallel. The probe 1 is supported by a position detection device 2 so that its position and orientation can be detected.

The position detecting device 2 is configured as shown in FIG. 2, for example. Reference numeral 50 denotes a support that can be freely moved by a pulley 51. A support 52 is provided on the upper surface of the support 50 so as to be pivotable along one axis parallel to the Z-axis. An arm 53 is provided so as to be able to move up and down along two axes parallel to the X axis. At the tip of this arm 53, an arm 54 is provided rotatably along three axes parallel to the X axis. An L-shaped L-shaped block 56 is rotatably connected to a tip of the arm 54 via a block 55 along four axes parallel to the Y-axis, and is attached to one end of the L-shaped block 56 via a block 57. Block 58 is orthogonal to 4 axes 5
It is connected rotatably along the axis. The mounting block 58 rotatably mounts the probe 1 along six axes orthogonal to the five axes. Therefore, the position detecting device 2 can support the probe 1 at an arbitrary position and an arbitrary posture, and furthermore, the current position P ₀ (x ₀ ,
y ₀ , z ₀ ) and posture, that is, the inclination angle α of the long axis of the probe 1 with respect to the X axis, the inclination angle β of the long axis of the probe 1 with respect to the Y axis, and the inclination angle γ of the long axis of the probe 1 with respect to the Z axis. You can do it. The information on the current position and posture of the probe 1 detected by the position detection device 2 is referred to as position data and used in the following description.

A transmission system 3 and a reception system 7 are connected to the probe 1. The transmission system 3 includes a pulse generator 4, a transmission delay circuit 5, and a pulser 6, and supplies a transmission pulse to each transducer of the probe 1 during transmission. The pulse generator 4 generates a rate pulse. The transmission delay circuit 5 gives the rate pulse received from the pulse generator 4 a different delay time for each transducer to focus the ultrasonic beam in a predetermined direction. The pulser 6 supplies a transmission pulse to each transducer of the probe 2 according to the delay rate pulse from the transmission delay circuit 5.
When an ultrasonic beam is transmitted from the probe 1 into the subject P by a transmission pulse from the transmission system 3, the ultrasonic beam is reflected at a boundary portion of a different acoustic impedance in the subject P and is received by the probe 2 again. This reception signal is supplied to the reception system 7.

The receiving system 7 includes a preamplifier 8, a receiving delay circuit 9, and an adder 10. The preamplifier 8 amplifies the received signal to a predetermined level. The reception delay circuit 9 receives the reception signal amplified by the preamplifier 8 and gives the reception signal a delay time opposite to the delay time given by the transmission delay circuit 5. The adder 10 adds the outputs from the reception delay circuit 9. This addition signal is supplied to a B-mode processing system 11 and a color flow mapping (CFM) processing system 15.

The B-mode processing system 11 includes a logarithmic amplifier 12,
Envelope detection circuit 13, analog-to-digital converter (A /
D) 14 is provided. The logarithmic amplifier 12 receives the added signal from the receiving system 7 and logarithmically amplifies the signal. The envelope detection circuit 13 detects the envelope of the output from the logarithmic amplifier 12. The detection signal from the envelope detection circuit 13 is transmitted to the B-mode processing system 11 through the analog / digital converter 14.
Output from

The color flow mapping processing system 15 includes a phase detection circuit 16, an analog-to-digital converter 17, and a moving target indicator (MTI).
arget Indicator) A filter 18, an autocorrelator 19, and a calculation unit 20 are provided. The phase detection circuit 16 receives the addition signal from the reception system 7, removes high-frequency components therefrom, and performs quadrature phase detection processing. The output from the phase detection circuit 16 is sent to the MTI filter 18 via the analog / digital converter 17. MTI is a technique commonly used in the radar field, and is a technique for extracting only a set moving target using the Doppler effect. The MTI filter 18 is an application of the MTI technology, and based on a phase change between the same pixels in a rate pulse repeatedly transmitted a predetermined number of times, a relatively moving object such as a heart wall included in a received signal. An unnecessary clutter component from a slow moving object is removed, and only a reflection component from a moving target, that is, a blood cell is extracted.

The autocorrelator 19 uses the output from the MTI filter 18 to perform frequency analysis in real time on the output levels of two-dimensional multiple points. Autocorrelation processing is FFT
(Fast Fourier Transform) This is a process that is frequently used in devices that require real-time processing because frequency analysis can be realized with a significantly smaller number of operations than in the process. Arithmetic unit 20
Receives the output of the autocorrelator 19 and calculates information such as the average speed, variance and power of each point. This information is 2
It is sent to a dimensional digital scan converter (DSC) 21.

The digital scan converter 21 has a B
Upon receiving outputs from the mode processing system 11 and the CFM processing system 15, two-dimensional B-mode images and CFM images are separately generated. This digital scan converter 21 has 2
A two-dimensional image display system 22 and a three-dimensional image display system 26 are connected. The display system 22 includes a color processing circuit 23, a digital / analog (D / A) converter 24, and a color monitor 25, and displays a B-mode image and a CFM image from the digital scan converter 21 in black and white or in color, respectively.

The other display system 26 is a three-dimensional digital scan converter (3D-DS) which is a main part of the present invention.
C) 27, digital / analog (D / A) converter 28,
A color monitor 29 is provided, creates a three-dimensional image combining the B-mode image and the CFM image, and displays it.

3D digital scan converter 27
Is configured as shown in FIG. That is, the three-dimensional digital scan converter 27 is connected to the central processing unit (CP
U) 33 as a center of control of each component and three-dimensional image processing, a CPU bus 34 from the central processing unit 33.
Each component is connected in a branch shape. Each B-mode image from the digital scan converter 21 is supplied to a switch 35.
By the switching operation, the image data is stored in the B image image memories 361 to 36n prepared for the number of slices. These B image image memories 361 to 36n are connected to the CPU bus 3
4 are interconnected. Similarly, the CFM images from the digital scan converter 21 are held in the CFM image image memories 381 to 38n prepared for the number of slices by the switching operation of the switch 37. These CFM
The image memories 381 to 38n for images are stored in the CPU bus 34.
Interconnected.

The above-mentioned position detecting device 2 is connected to the CPU bus 34, and the position data of the position and the posture of the probe 1 detected by the position detecting device 2 are inputted.
The system controller 31 described above is connected to the CPU bus 34, and the trace information of the contour of the region of interest input from the operation switch 30 is input.

The CPU bus 34 is connected to a B image three-dimensional data memory 39 and a CFM image three-dimensional data memory 40 having a three-dimensional memory space corresponding to a real space. The trace information of the contour of the region of interest input from the operation switch 30 via the system controller 31 is based on the position data of the probe 1 when the B-mode image was collected under the writing control of the central processing unit 33. The dimensional coordinates are converted and sequentially written to corresponding positions in the three-dimensional memory space of the B-image three-dimensional data memory 39. Also, image memories for CFM images 381 to 38n
Of each of the CFM images is extracted by the central processing unit 33, and under the writing control of the central processing unit 33, the CFM image is subjected to three-dimensional coordinate conversion based on the position data of the probe 1 when the B-mode image is collected. Is sequentially written to a corresponding position in the three-dimensional memory space of the three-dimensional data memory 40 for use.

Further, a plurality of and the same number of B image projection memories 411 to 41m and CFM image projection memories 421 to 42m are connected to the CPU bus 34. 3 for B image
The three-dimensional distribution information in the dimensional data memory 39 is projected from a plurality of viewpoints set by the central processing unit 33, and these projected images are sent to and stored in the B image projection memories 411 to 41m, respectively. Similarly, the three-dimensional distribution information of the CFM image three-dimensional data memory 40 is projected from the same plurality of viewpoints as when the three-dimensional distribution information of the B image three-dimensional data memory 39 is projected. Each CF
The images are sent to and stored in the M image projection memories 421 to 42m.

A switch 43 is connected to the B image projection memories 411 to 41m, and the CFM image projection memories 421 to 4m.
A switch 44 is connected to 2m. The switch 43 and the switch 44 selectively output two types of projected images projected from the same viewpoint one by one to the color processing circuit 45 in synchronization with each other. The color processing circuit 45 combines the two projected images, converts the combined image into R, G, and B color signals using a color bar and outputs the signals.

A three-dimensional digital scan converter 27
The composite image output from the color processing circuit 45 is displayed on a color monitor 29 via a digital / analog converter (D / A) 28.

Reference numeral 30 denotes B displayed on the color monitor 29.
An operation switch (S) such as a mouse or a divider for manually tracing the contour of the region of interest (tumor) in the mode image
W). Trace information (operation trajectory) from the operation switch 30 is sent to the three-dimensional digital scan converter 27 via the system controller 31. The three-dimensional digital scan converter 27 superimposes the trace information on the currently held B-mode image, and displays the superimposed image on the color monitor 29. Next, the operation of the present embodiment will be described.

The probe 1 is moved by the operator to the subject P
The body surface is moved. At each position, the probe 1 is driven by the transmission system 3 and repeats a two-dimensional scan. The echo information obtained by each of the two-dimensional scans is sent to a B-mode processing system 11 and a color flow mapping processing system 15.
Digital scan converter 2 generated into FM image
Sent to 1.

At this time, the position and orientation of the probe 1 at each position when the two-dimensional scan is repeated are detected by the position detecting device 2. This position data is sent to the three-dimensional digital scan converter 27.

Each B-mode image and each CFM image are sequentially output from the digital scan converter 21 to the three-dimensional digital scan converter 27. The three-dimensional digital scan converter 27 converts each B-mode image into a switch 3
5, the B image image memory 3
61 to 36n, and switches each CFM image to a switch 37.
Are sequentially stored in the CFM image image memories 381 to 38n.

Then, the three-dimensional digital scan converter 27 generates a three-dimensional image using these stored images. FIG. 4 shows a three-dimensional digital scan converter 2
FIG. 7 is a diagram showing a schematic flow of a three-dimensional image generation process by No. 7;

First, the three-dimensional digital scan converter 27 converts each of the CFM images stored in the CFM image image memories 381 to 38n into multi-valued data, here quaternary data, and extracts a blood vessel image. Note that it is relatively easy to extract a blood vessel image from a CFM image. Because MT already
Since only the blood flow component is extracted by the I filter 18 and the images on the CFM image are all blood vessel images, the blood vessel portion can be extracted by performing the threshold processing with a relatively rough threshold. The CFM image shows the direction, velocity,
Since it has blood flow information such as dispersion, here CFM
The pixel value of each pixel of the image is replaced with any of the following four types of data. 0: out of the scan range 1 ... no blood flow 2 ... blood flow coming 3 ... blood flow going away

On the other hand, it is very difficult to binarize a B-mode image and extract the contour of a site of interest such as a tumor, and at present, there is no method that can be completely automated. Therefore, here, the image memories 361 to 3 for B-mode images are used.
6n is stored in the color monitor 2
9 and the outline of the concerned part of each B-mode image is traced manually by the operator using the operation switch 30 such as a mouse. Note that the pixel value of the pixel on the contour line is replaced with 2, and the pixel value of the pixel of the other background portion is replaced with 0.

Next, the quaternary image and the binary image of each slice described above are developed in the three-dimensional memory space of the three-dimensional data memory 39 for the B image and the three-dimensional data memory 40 for the CFM image, respectively. The three-dimensional coordinate conversion process required for this expansion process is performed as follows.

That is, the position data of each position of the probe 1 which has been two-dimensionally scanned is supplied from the position detecting device 2 to the central processing unit 33. As described above, the position data is the current position P ₀ (x ₀ , y ₀ , z ₀ ) of the probe 1 and the angles (α, β, γ) with respect to the X, Y, and Z axes.
The central processing unit 33 converts the two-dimensional coordinates of each quaternary image and each binary image into three-dimensional coordinates using the position data of each slice. FIG. 5 shows a three-dimensional data memory 3 for a B image.
9 is a diagram schematically showing a three-dimensional memory space of a three-dimensional data memory for CFM 9 and CFM images. The reference position of each image is P ₀ (x ₀ , y ₀ , z ₀ ) detected in each slice. (X, Y) is the address of the two-dimensional image, (x, Y)
(y, z) is the address of the three-dimensional space after the three-dimensional coordinate conversion.

First, a rotation parameter A about the X axis in the three-dimensional space is expressed by the following equation (1), and a rotation parameter B about the Y axis is expressed by the following equation (2). The rotation parameter C is represented by the following equation (3).

[0034]

(Equation 1)

Therefore, from (X, Y) to (x, y,
The three-dimensional coordinate conversion to z) can be expressed by equation (4). In equation (4), (x ₀ ′, y ₀ ′,
z ₀ ′) is calculated from the P ₀ (x ₀ , y ₀ , z ₀ ) from the P _{0 of} the slice located at the center of all the slices in the three-dimensional scan (for example, the 50th slice in the case of 100 slice scan). ₀ (x ₀ , y ₀ , z ₀ ) is subtracted.

[0036]

(Equation 2)

However, this three-dimensional coordinate conversion is performed on the XYZ coordinate system recognized by the position detecting device 2,
As will be described later, the projection image has a viewpoint of x in a three-dimensional memory space.
Since it is created while rotating around the y axis of the yz coordinate system, the following coordinate transformation is further performed to change the y axis to the center of rotation, in other words, to move the viewpoint around the y axis. Here, the coordinate conversion processing is performed so that the slice at the center of the three-dimensional scan becomes the center of the rotation axis. Assuming that the rotation angles α _c , β _c , and γ _c of the slice at the center of the three-dimensional scan are, rotation parameters A _c ⁻¹ , B _c ⁻¹ , and C _c for each axis of the x-axis, y-axis, and z-axis coordinate systems ^-1 can be defined as in the following equations (5), (6), and (7), respectively.

[0038]

(Equation 3)

The rotation parameters A _c ^-1 and B _{c
When c} ^-1 and C _c ^-1 are applied to (x, y, z) obtained by Expression (4) as shown in Expression (8), xy in the three-dimensional memory space is obtained.
The three-dimensional coordinates (x ', y', z ') of the z coordinate system can be obtained.

[0040]

(Equation 4)

It should be noted that (A _c ^-1 · B _c ^-1 · C _c ^-1 ) · (C
Since the original two-dimensional coordinates need only be transformed for the matrix of (B · A), the processing time hardly changes even if the viewpoint is moved.

The central processing unit 33 performs this three-dimensional coordinate conversion on all the pixels (X, Y) of the binary image or the quaternary image to convert them to three-dimensional coordinates. Based on these three-dimensional coordinates,
The binary image is developed in the three-dimensional memory space of the B image three-dimensional data memory 39, and the quaternary image is developed in the three-dimensional memory space of the CFM image three-dimensional data memory 40.

Next, an interpolation process is performed on an area of the three-dimensional memory space in which the data after the three-dimensional coordinate conversion is not written. Since the center slice of the three-dimensional scan is on the xy plane by the above viewpoint conversion, it is considered that the z-axis direction is almost the orthogonal direction (slice direction) of the ultrasonic scan. Since the slice pitch is significantly larger than the scanning line pitch of the two-dimensional scan, the resolution in the slice direction is poor in terms of the sound field, and it is desirable that the interpolation process be performed along the slice direction. This interpolation processing is individually performed for each piece of three-dimensional distribution information in the three-dimensional data memory 39 for B-mode images and the three-dimensional data memory 40 for CFM images.
The interpolation process is performed as follows. That is, the value of each pixel is continuously searched in parallel with the z-axis. At this time, when there is a point having a pixel value of 0 between two points having a pixel value of 1 or more (that is, a pixel having no image information is sandwiched between pixels having image information), Interpolation processing is performed by selectively replacing a large value of two points having a pixel value of 1 or more with a pixel value of 0 at a location. However, if there are at least a certain number of points having a pixel value of 0 (for example, 32 points) between one or more two points, it is determined that the image is discontinuous, and interpolation processing is performed for the point having the pixel value of 0. Not performed.

By the above processing, a three-dimensional blood vessel image can be obtained.
When the three-dimensional tumor contour image is stored in the B-mode image three-dimensional data memory 39 and the CFM image three-dimensional data memory 40, an image for three-dimensional display, that is, a plurality of projection images having different viewpoints is obtained. The creation process is started. In this case, the three-dimensional distribution information is projected at the same position while moving the viewpoint in the same three-dimensional memory space of the three-dimensional data memory 39 for the B-mode image and the three-dimensional data memory 40 for the CFM image. By creating a plurality of projection images and displaying each projection image at predetermined time intervals in the order along the movement path of the viewpoint, it is as if a three-dimensional model of a blood vessel and tumor rotates using human motion parallax It is displayed three-dimensionally. There are a plurality of display methods at this time, as described below, which are appropriately selected and used. [Display method 1]

The display method 1 is a basic display method of the present embodiment for displaying the surface image of the contour image of the tumor and the surface image of the blood vessel while rotating the viewpoint around the y-axis. The hue and luminance processing at this time are performed such that the outline of the tumor is expressed in gray, the blood vessels coming toward it in red, and the blood vessels moving away in blue, and the brightness is changed according to the distance from the viewpoint. This allows the operator to perceive three-dimensionally as if the three-dimensional model of the blood vessel and the tumor were rotated by the motion parallax. 6A and 6B are diagrams showing a display order according to this display method. FIG. 6A is an image when the position of the viewpoint is an initial position around the y-axis, that is, at an angle of 0 °, and FIG.
(C) is an image at 90 °. In practice, it is desirable to create projection images at 5 ° intervals and display them continuously, as if the tumor and surrounding blood vessels rotate continuously in a three-dimensional space. [Display method 2]

The display method 2 is a display method in which a part of a tumor image is cut in the display method 1 to create a projection image and the projection image is displayed. For example, an image of FIG. 6A in which a part of the tumor is cut is as shown in FIG. 7A. [Display method 3] Display method 3 is a display method in which the tumor image of display method 1 is displayed translucently. This image is as shown in FIG. [Display method 4]

Display method 4 is a display method of display method 1 (tumor surface display, blood vessel surface display) or display method 3 (tumor translucent display, blood vessel surface display) with the viewpoint set inside the tumor. is there. Display method 1 with the viewpoint set inside the tumor
7C is as shown in FIG. 7C, and the image when the display method 3 is applied is as shown in FIG. 7D. [Display Method 5] In Display Method 2, a B-mode image is inserted into a portion where a part of a tumor image is cut by simply converting the cross section. This image is as shown in FIG. Next, a processing procedure for implementing each of the above display methods will be described.

First, the processing procedure of the display method 1 will be described. The B-mode image three-dimensional data memory 39 and the CFM image three-dimensional data memory 40 hold three-dimensional distribution information of a blood vessel image and a tumor contour image developed in a three-dimensional memory space. Since all the processing procedures are the same, only the processing procedure of the blood vessel image will be described here, and the processing procedure of the contour image of the tumor will be omitted. A projection image for rotational display is created at each position while moving the viewpoint with respect to the three-dimensional distribution information of blood vessels. The coordinate (x, Y, Z) before rotation with respect to the coordinate (X, Y, Z) after rotation when the viewpoint is rotated by an angle θ around the y axis.
y, z) is obtained by the following equation (9).

[0049]

(Equation 5)

Next, a projected image viewed from the Z-axis direction of the rotated XYZ coordinate system is obtained. Here, the projection processing is performed by parallel projection in which all projection lines are parallel to the Z axis.
The central processing unit 33 sequentially searches for a pixel from a larger Z-axis to a smaller one. When a pixel having a pixel value of 2 or more appears, the search is stopped, and the Z coordinate of the pixel and the The pixel values are stored in the CFM image projection memories 421 to 42.
m and is held at the (X, Y) position. This processing procedure is realized by a processing method generally called a z-buffer algorithm. In addition, here, for convenience, it is called a projection image, but to be precise, it is a surface display image from which hidden surfaces have been eliminated. A search is performed along the projection line to the last pixel in the three-dimensional memory space, and when the pixel values of all the pixels are 0, the CFM image projection memories 421 to 42m
0 is placed at the corresponding (X, Y) position in the same memory. If there is a pixel having a pixel value of 1 in the middle, 1 is inserted at the corresponding (X, Y) position in the same memory. Such projection processing is repeated at each position while rotating the viewpoint. These plurality of projection images are respectively C
These are sequentially stored in the FM image projection memories 421 to 42m. For example, when the intermittent rotation angle θ is changed every 5.625 °, the above-described projection processing is repeated 64 times to display 360 °, and the obtained 64 projected images are respectively projected to the CFM image. The data is held in the memories 421 to 42m.

The projection image of the contour image of the tumor is also created in the same manner as the processing procedure of the blood vessel image, and is sequentially stored in the B-mode image projection memories 411 to 41m in accordance with the moving order of the viewpoint.

At the time of display, the switching devices 43 and 44 perform switching operation in synchronization with each other, so that the projection images of the B-mode image projection memories 411 to 41m and the CFM image projection memory 421 created from the same viewpoint. .About.42 m are sequentially supplied to the color processing circuit 45 one by one.

[0053] In the color processing circuit 45, B-mode image projection memory 411 tumors of the contour of the projected image from ～41M (pixel values of pixels (Z _B, D _B)) and the projection memory 421 ～42M for CFM image Is combined with a projection image of a blood vessel (pixel values (Z _C , C _C ) of each pixel) from a single image.
Incidentally, Z _B and Z _C is the Z-coordinate of the appearance pixel projection processing, D _B and C _C is the value when binarization or four values. The color processing circuit 45 performs the following processing in the case of the display method 1. When D _B = 2, white information is given to the pixel of the composite image,
And providing the luminance in accordance with the Z _B Z coordinates. When DB _B2 and C _C = 0, gray information is given to the pixel of the composite image.

When D _B ≠ 2 and C _C = 1, black information is given to the pixel of the composite image. When D _B ≠ 2 and C _C = 2, red information is given to the pixel of the composite image, and luminance according to Z _C is given. When D _B ≠ 2 and C _C = 3, blue information is given to the pixel of the composite image and luminance according to Z _C is given. The plurality of images synthesized in this way are sequentially sent to a color monitor 29 via a digital-to-analog converter 28 and are continuously displayed.

In order to perform the [display method 2], it is necessary to first determine the cross section of the tumor to be cut. As a determination method, manual and automatic are selected and used. In the manual, a projected image having an optimum cross section is first selected while looking at the rotated image of [Display method 1]. Next, in order to determine the depth of the section to be cut, the part of the tumor image is designated with a mouse. When the value of Z _B of the specified location and Z _BT,
By adding a process of “if Z _B > Z _BT , even if D _B = 2, the same process as in the case of D _Bに 2” is added to the above-described synthesis process, the depth is greater than Z _BT . The part of the tumor in front can be cut. In the case of auto,
By going to change the value of the Z _BT automatically little by little, it can be displayed by changing the cross-section cut continuously. The combining process in [Display method 3] is performed under the following conditions. When D _B ≠ 2 and C _C = 0, gray information is given to the pixel of the composite image. When D _B ≠ 2 and C _C = 1, black information is given to the pixel of the composite image. When D _B ≠ 2 and C _C = 2, red information is given to the pixel of the composite image and luminance according to Z _C is given. When D _{B 、} 2 and C _C = 3, blue information is given to the pixel of the composite image and luminance according to Z _C is given. When D _B ≠ 2 and C _C ≦ 1, white information is given to the pixel of the composite image and luminance according to Z _B is given. When D _B ≠ 2 and C _C = 2, red-violet information is given to the pixel of the composite image and luminance according to Z _C is given. When D _{B 、} 2 and C _C = 3, blue-violet information is given to the pixel of the composite image, and a luminance according to Z _C is given. By this synthesizing process, the blood vessels hidden behind the tumor from the viewpoint are expressed in purple-based colors, and the existence thereof can be confirmed. In order to perform the [display method 4], the projection lines may be radially arranged from the viewpoint inside the tumor, and the search may be performed from the viewpoint toward the outside of the tumor.

In order to perform the [display method 5], the B-mode image is not binarized, and the data with the gradation of the original B-mode image is stored in the three-dimensional data memory 39 for the B-mode image.
Is read out from the B-mode image three-dimensional data memory 39 and combined with the projected image of the blood vessel.

As described above, according to this embodiment, three-dimensional display can be performed by combining the B-mode image and the CFM image. As a result, the following clinical utility can be achieved. 1) For example, it is possible to specify a vegetative blood vessel providing nutrition to the tumor, for example, whether the tumor receives nutrition from the hepatic artery, hepatic vein, or portal vein. 2) Since the three-dimensional structure of tissues and blood vessels can be transmitted and recorded as objective information, it can be used for conferences and explanations to patients. 3) The three-dimensional structure of a tissue or a blood vessel can be directly displayed, so that a diagnosis time can be reduced and a diagnosis accuracy can be improved. 4) Since an image of a tumor can be combined with an image of a blood vessel around the tumor and displayed three-dimensionally, an operation plan such as determination of an extraction range can be made superior. 5) Since the image of the tumor and the image of the vegetative blood vessel can be combined and displayed three-dimensionally, it is easy to determine the quality of the therapeutic effect after treatment such as ethanol embolization. 6) Since the image of the tumor and the image of the vegetative blood vessel can be combined and displayed three-dimensionally, it is easy to determine whether the tumor is benign or malignant. The present invention is not limited to the embodiments described above, but can be implemented with various modifications.

[0058]

The present invention provides a means for scanning an ultrasonic probe for transmitting and receiving ultrasonic waves in a desired three-dimensional space in a subject while moving the ultrasonic probe, and a means for detecting the position and orientation of the probe. Means for obtaining tissue information in the three-dimensional space and movement information of a moving object in the three-dimensional space based on a signal received from the probe; and means for extracting a contour image of a portion of interest from the tissue information. Means for extracting a blood flow image from the movement information; and distributing the contour image and the blood flow image in a three-dimensional space based on the position and orientation information of the probe from the detecting means. Means for projecting the three-dimensional distribution information at each position while changing the viewpoint with respect to the three-dimensional space to generate a plurality of two-dimensional images. Display continuously ; And a stage.

Therefore, according to the present invention, three-dimensional distribution information is created by distributing the contour image of the part of interest and the blood flow image extracted from the tissue information in a three-dimensional space, and changing each viewpoint while changing the viewpoint. Projection processing of three-dimensional distribution information at a position
By generating two-dimensional images and displaying these two-dimensional images continuously in a predetermined order, the three-dimensional structure of the part of interest and the three-dimensional structure of the blood flow image are simultaneously observed by a visual characteristic called human motion parallax. For example, the relationship between a tumor and its vein can be grasped.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of an ultrasonic diagnostic apparatus according to the present invention.

FIG. 2 is an external view showing the structure of the position detection device shown in FIG.

FIG. 3 is a block diagram showing a configuration of the three-dimensional digital scan converter shown in FIG.

FIG. 4 is an exemplary view showing a processing procedure of three-dimensional display according to the embodiment.

FIG. 5 is a view for explaining three-dimensional coordinate conversion processing by the central processing unit shown in FIG. 3;

FIG. 6 is a view showing a rotation display according to the embodiment.

FIG. 7 is a view showing another display method according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Position detection device, 3 ... Transmission system, 7 ... Reception system, 11 ... B-mode processing system, 15 ... CFM processing system, 2
1 ... Digital scan converter, 22, 26 ... Display system, 27 ... Three-dimensional digital scan converter.

Continuation of the front page (56) References JP-A-2-124148 (JP, A) JP-A-62-150385 (JP, A) JP-A-4-1588853 (JP, A) JP-A-54-143041 (JP, A) JP-A-4-174655 (JP, A) JP-A-2-36851 (JP, A) JP-A-56-70757 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) A61B 8/00-8/15

Claims (6)

(57) [Claims] A probe for transmitting and receiving an ultrasonic wave to and from a subject; obtaining tissue information in the three-dimensional space and movement information of a moving body in the three-dimensional space based on a reception signal from the probe. Means for extracting a contour image of a portion of interest from the tissue information; means for extracting a blood flow image from the movement information; and storing three-dimensional distribution information of the contour image and the blood flow image.
A two-dimensional data memory; generating means for projecting the three-dimensional distribution information at each position while changing the viewpoint with respect to the three-dimensional space to generate a plurality of two-dimensional images; An ultrasonic diagnostic apparatus, comprising: display means for continuously displaying the ultrasonic diagnostic data. 2. The generating means extracts data on the contour image or data on the blood flow image appearing first from the viewpoint from the three-dimensional distribution information by the projection processing, and The ultrasonic diagnostic apparatus according to claim 1, wherein the ultrasonic diagnostic apparatus generates a two-dimensional image. 3. An ultrasonic diagnostic apparatus according to claim 1, wherein said generating means further comprises means for removing a part of said contour image from said two-dimensional image. 4. The ultrasonic diagnostic apparatus according to claim 1, wherein the display unit displays the two-dimensional image while changing at least one of a color tone and a luminance according to a distance from the viewpoint. 5. The ultrasonic diagnostic apparatus according to claim 1, wherein said generating means generates said two-dimensional image by positioning said viewpoint inside said contour image. 6. The means for extracting a contour image of a part of interest includes means for tracing the contour of the part of interest in accordance with an instruction of an operator, and means for generating the contour image based on the traced contour. The ultrasonic diagnostic apparatus according to claim 1, further comprising: